FILE - In this June 8, 2012, file photo, Republican presidential candidate and former Massachusetts Gov. Mitt Romney, left, walks alongside U.S. Senator Orrin Hatch, R-Utah on the tarmac of Salt Lake City International Airport, in Salt Lake City. Romney plans to announce his Utah Senate campaign Thursday, Feb. 15, 2018. Three people with direct knowledge of the plan, say Romney will formally launch his campaign in a video. The 70-year-old Republican is seeking to replace Hatch, who is retiring after more than 40 years in the U.S. Senate. (AP Photo/Colin E. Braley, File)

FILE - In this Nov. 5, 2012, file photo, shows Republican presidential candidate, former Massachusetts Gov. Mitt Romney gives a speech to supporters at the Sanford International Airport in Sanford, Fla. Romney's run for U.S. Senate in Utah is his latest bid for public office since he first jumped into politics more than 20 years ago. (Scott Keeler/Tampa Bay Times via AP)

FILE - In this Aug. 12, 2012, file photo, shows Republican presidential candidate, former Massachusetts Gov. Mitt Romney, greeting supporters as he arrives at campaign event in High Point, N.C. Romney's run for U.S. Senate in Utah is his latest bid for public office since he first jumped into politics more than 20 years ago. (AP Photo/Mary Altaffer, File)

FILE - In this Jan. 8, 2008, file photo, Republican Presidential hopeful, former Massachusetts Gov. Mitt Romney greets a voter heading to the polls at Brookside Congregational Church to vote in the New Hampshire Presidential Primary in Manchester, N.H. Romney's announcement Thursday, Feb. 15, 2018, of a run for U.S. Senate seat in Utah is his latest bid for public office since he first jumped into politics more than 20 years ago. (AP Photo/LM Otero, File)

FILE - In this Jan. 31, 2008, file photo, Republican presidential hopeful, former Massachusetts Gov. Mitt Romney, campaigns at Bassett Furniture in Fountain Valley, Calif. Romney's announcement Thursday, Feb. 15, 2018, of a run for U.S. Senate seat in Utah is his latest bid for public office since he first jumped into politics more than 20 years ago. (AP Photo/LM Otero, File)

FILE - In this Sept. 18, 2003, file photo, Massachusetts Gov. Mitt Romney laughs as he poses with sixth, seventh and eighth graders from the Boston Renaissance Charter School in Boston. Romney's run for U.S. Senate in Utah is his latest bid for public office since he first jumped into politics more than 20 years ago. (AP Photo/Elise Amendola, File)

FILE - In this Feb. 25, 2003, file photo, Massachusetts Gov. Mitt Romney delivers his State of the State address in Boston. Romney's run for U.S. Senate in Utah is his latest bid for public office since he first jumped into politics more than 20 years ago. (AP Photo/Elise Amendola, File)

FILE - In this Sept. 17, 2001, file photo, shows Mitt Romney, president of the Salt Lake Organizing Committee, with the new Olympic "We Stand United" pin during a news conference, in Salt Lake City. Romney's run for U.S. Senate in Utah is his latest bid for public office since he first jumped into politics more than 20 years ago. (AP Photo/Douglas C. Pizac, File)

FILE- In this Oct. 10, 1994, file photo, Republican U.S. Senatorial candidate Mitt Romney greets supporters at the Columbus Day parade in Worcester, Mass. Romney's run for U.S. Senate in Utah is his latest bid for public office since he first jumped into politics more than 20 years ago. (AP Photo/C.J. Gunther, File)

FILE - In this Jan. 19, 2018,, file photo, former Republican presidential candidate Mitt Romney waves after speaking about the tech sector during an industry conference, in Salt Lake City. Romney plans to announce Utah Senate campaign Thursday, Feb. 15, 2018. Three people with direct knowledge of the plan say Romney will formally launch his campaign in a video. (AP Photo/Rick Bowmer, File)

SALT LAKE CITY (AP) — Mitt Romney's expected run for a U.S. Senate seat in Utah will be his latest bid for public office since he first jumped into politics more than 20 years ago.

Romney had planned to announce his candidacy Thursday but said Wednesday night on Twitter that he would delay it because of the deadly school shooting in Florida. It wasn't clear when he would reschedule.

The former businessman, who is expected to be a heavy favorite in the Utah race, has endured more setbacks than victories since he launched his political journey in the early 1990s, following in the footsteps of his parents who ran decades earlier for governor, president and a U.S. Senate seat in Michigan.

A look at Romney's campaigns through the years:

U.S. SENATE IN MASSACHUSETTS, 1994

Result: Lost.

What happened: Romney took leave from his private equity firm to challenge Ted Kennedy for the Massachusetts seat that the Democrat held at that point for more than three decades. Romney, running as a Republican in a blue state, supported abortion rights and gun control measures and said he would offer more effective leadership on gay rights issues than Kennedy. Romney lost, 58 percent to 41 percent, but won more of the vote than any other Republican who challenged Kennedy in his 40 years in Senate.

MASSACHUSETTS GOVERNOR, 2002

Result: Won.

What happened: Coming off his successful turnaround of Salt Lake City's scandal-plagued 2002 Winter Olympics, Romney returned to Massachusetts and edged acting Gov. Jane Swift out of the Republican race for governor. Romney, positioning himself as moderate and highlighting his business experience, defeated Democrat Shannon O'Brien, 50 percent to 45 percent. He served four years and signed health care reform into law designed to guarantee virtually all state residents access to insurance.

PRESIDENT, 2008

Result: Lost in GOP presidential primary.

What happened: After his stint as governor, Romney set his sights on higher office and jumped into a crowded GOP field of presidential contenders. He faced apprehension from some conservative and evangelical Christians over his Mormon faith and past support for abortion rights. Romney dropped out of the primary race in February 2008 as Arizona Sen. John McCain swept more states.

PRESIDENT, 2012

Result: Won GOP presidential primary, but lost general election.

What happened: Romney regrouped after his 2008 campaign and re-emerged as a front-runner in the 2012 Republican presidential race. Stressing his business acumen and staying critical of President Barack Obama, Romney became his party's nominee but lost in November as voters sent Obama back for a second term.

U.S. SENATE IN UTAH, 2018

Result: To be determined.

What happened: Romney has decided to get back into politics, planning to launch his run for the Utah seat held by longtime Sen. Orrin Hatch, who's retiring. The 70-year-old Romney is a heavy favorite to win and keep the seat in Republican hands. He is one of the most famous Mormons and is widely respected in Utah, which is heavily Mormon and home to the headquarters of The Church of Jesus Christ of Latter-day Saints. His work salvaging the 2002 Winter Olympics in Salt Lake City also bolstered his reputation in the state, where he moved after losing the 2012 presidential election. The Senate run comes after Romney flirted with joining the GOP presidential primary in 2016 amid Republican concerns about Trump becoming the front-runner.